To be better at English, you must have patience, learn and use English over and over, and never give up. It is better to study and use English every day for a convenient amount of time than to spend one day a week using English the whole time. Some people find pen pals, native speakers from other countries to communicate with on a constant basis. They use social networking sites to make new friends. Of course, in South Korea there are so many native-speakers around, so it is quite easy to set up non-paid (language exchange, etc.) or paid tutoring to get extra help for your English ability. And if you really want a great way to be an all-around better English speaker, then you could research how to find a learning program in a native-speaking country, through your university or to set-up a working holiday in another country that uses English (many Koreans are turning to Australia, as it is easy to work there as a foreigner). My advice to students who go to another country to become better at English is to NOT go to a major city in which many other Koreans live, as you might only surround yourself with Koreans outside of class and not use English. Below are more tips on how to improve your English.
The main idea to understand is constant exposure. Don't limit your learning to one English class! Listen to English radio, watch TV programs with English subtitles (or without), read English books that are at your ability level. Of course, make sure you have a dictionary available to help you understand words. But when reading or listening to English, in many cases it is possible to learn the meaning of words through context. This means to look at the words used with the word you don’t know. For example, look at this sentence: His dinner was certainly not a square meal.He only ate a piece of bread and a small cup of tea. Now, most basic learners of English would be confused by this sentence, and quickly pick up a dictionary, as most learners know the word ‘square’ to mean a shape with 4 equal sides. But in this context, ‘square’ means a substantial, nourishing meal. It is a good habit for English students to try to understand a word by its context before quickly picking up a dictionary. Of course, when students take an English test like TOEIC they won’t be able to use a dictionary, so it is a good idea to use this skill to understand meaning.
In the early stages of learning, focus more on fluency (meaning). Don't worry about perfect grammar (accuracy); little mistakes are ok in the beginning, as long as they do not become permanent mistakes. The best students I've had were not afraid to make mistakes, and really tried to correct mistakes whenever possible. But most importantly, they didn't worry about perfection. They were persistent learners, and never gave up. If you want to be corrected as often as possible, be sure to communicate with your instructor (or native-speaking friend) your request. It is not generally healthy for your English learning for your instructor to correct your errors 100% of the time, as it might affect a learner’s confidence. Being corrected, however, helps to prevent fossilized errors, which are errors a student makes that are hard for the student to change in later English learning levels (even after being corrected) because the student was never corrected on the errors in the early stages of learning. Some advanced learners of English make errors from the intermediate level or beginner levels on some structures, which are fossilized errors. However, some teachers correct mistakes constantly during grammar lessons, but don’t correct as much during conversation classes, as fluency is more important in those types of classes.
To become better at grammar, find a grammar textbook with exercises to practice. Speak with native speakers or join a class to improve your speaking ability with grammar, and perhaps a native speaker pen pal could help you with any mistakes. English grammar can be quite difficult, as there are many exceptions to rules, but with constant practice, a student will improve.
To become better at vocabulary, write down any words you come across on a daily basis and study the definitions. You could even make flashcards (write the word on one side, and the definition on the other) to practice. You could just focus on ten words a day. For pronunciation practice, learn carefully about the position of the mouth and tongue while pronouncing words. The University of Iowa is one university that offers a free website for pronunciation practice, but one might be able to find others online. Through constant practice, words will become easier as your mouth and tongue become more familiar with the new words.
To become better at listening, constantly listen to TV shows in English, and practice listening exercises. When watching an English TV show (with Korean subtitles), try to focus on the words spoken without looking at the subtitles, and then see if you can understand the words that have been spoken (you can go back and check to be sure).
Remember that everyone learns at their own speed and that some will learn faster than others. Be patient and keep practicing and learning. You will get better!